The invention is related to the centralized management of several telecommunications devices of different types, for example, of different manufacturers.
In some network management systems, the network elements such as radio repeaters are connected to the network management system (NMS) using a modem connection. Through the modem connection, the network management system sends to radio repeaters configuration parameters such as the radio channels to be used, the transmission power, the phone number of the modem of the management system, etc. Correspondingly, the radio repeaters send the management system alarms indicating error situations and faults and acknowledgments of the configuration messages received from the NMS.
When communicating with the management system, the repeater always uses a certain message structure which corresponds to the management protocol of the repeater type. Examples of these kinds of message structures are presented in FIGS. 1, 2A, and 2B.
FIG. 1 presents a message type in accordance with a possible management protocol used for controlling repeaters. The message begins with a sender identifier (6 characters) followed by a receiver identifier (6 characters). After these are fields for password (4 characters) and the length of a message text (2 characters). Then follow a function code (1 character), its specifier (1 character) and the text field of a maximum of 20 characters. At the end of the message there are a time field (8 characters) and a verification field consisting of 1 character.
FIGS. 2A and 2B present message types in accordance with another possible management protocol used for controlling repeaters. Messages of the type shown in FIG. 2A are used for alarms raised by the repeaters and the message type in FIG. 2B for configuration messages transmitted by the management system and for the acknowledgments transmitted by the repeaters as answers to the configuration messages.
The alarm message in FIG. 2A begins with a message identifier, which is always 00 identifying alarm messages. After the identifier there is the identity information of the repeater (4 characters) and 2 characters stating the length of the text field. After these follow the alarm number (2 characters), a text field of a maximum of 24 characters, the time (8 characters) and the verification field (1 character).
The message in FIG. 2B also begins with a message identifier, which is FF for a configuration message or AA for an acknowledgment message. After the identifier there are the identity information for the repeater (4 characters), the password (6 characters) and 1 character stating the length of the new value to be assigned for the setting to be configured. After these follow the identifier of the setting to be configured (1 character), the new value for the setting (6 characters maximum), the time (8 characters) and the verification field (1 character).
In addition to the message structure, the codes used by different types of repeaters, like alarm numbers and other identifiers, also vary. For example, the alarm number of an alarm stating that the input voltage level in the repeater is abnormal could be xe2x80x9c1xe2x80x9d in the system presented in FIG. 1 and xe2x80x9c1Cxe2x80x9d in the system presented in FIG. 2.
Repeaters and their management systems can typically use only one message type. Message types are almost always manufacturer-specific. Because of this, the repeaters and management systems of different manufacturers using different message types cannot communicate with each other.
In systems conforming to the technical level, a separate management system has been required for each repeater type. This kind of an arrangement is presented in FIG. 3 in which there are three repeaters: 1, 2 and 3, and the management systems used for them: NMS1 and NMS2 (NMS=Network Management System). Modems and a transmission network, which can be a telephone network, are used in the connections between the repeaters and the management systems. Repeaters 1 and 3 are of type 1 and they are controlled by using a compatible management system NMS1. Repeater 2 is of type 2 and it is controlled by using a compatible management system NMS2. Because of compatibility problems, repeaters 1 and 3 cannot be controlled by using management system 2 or repeater 2 by using management system 1.
The arrangement in FIG. 3 has many disadvantages. First, the network operator must purchase several management systems, which makes the investment expensive. Second, the personnel using the management system must be trained to use several different management systems. This requires much training and reserves personnel resources. The third disadvantage is the rigidity of the system in situations where the repeater configurations are dependent on each other. This kind of situation arises, for example, when the transmission power of repeater 1 is decreased and at the same time the transmission power of repeater 2 is increased by that same amount.
The objective of this invention is to remove these problems. This objective is achieved by using the arrangement and equipment described in the independent claims.
The idea of this invention is to control different types of network elements with the same management system by connecting the network elements into the management system using a conversion element. The control messages such as alarms and acknowledgments transmitted by the network element via a modem and being dependent on the network element type are directed to the conversion element. The conversion element converts the message transmitted by the network element into a format understood by the management system and then transmits the converted message to the management system. Correspondingly, the management system transmits the configuration messages to the conversion element in its own format. The conversion element converts the message, on the basis of information about the identity of the receiving network element, into the format used by the network element and transmits it forward.
For the message format conversion, the conversion element uses a conversion file. The conversion file contains information about the message formats used by the different network elements and how the contents of the fields are to be converted from one format to another. When new types of network elements are added to the network, the conversion file is updated by adding the information required for converting the message format of the new network element type into the message format understood by the management system.